Collagen ink for 3d printing

Abstract

A collagen ink for printing 3D structures includes a dispersion of native collagen fibers in an acid medium. The collagen ink can be obtained from a collagen-containing tissue. A method for 3-D printing includes neutralizing the collagen ink to a physiological pH, mixing the collagen ink with cells, and printing a 3D structure.

1 . A collagen ink for 3D printing, the collagen ink comprising a dispersion of native collagen fibers at a concentration between and 10% in an acid medium with a pH between 0.1 and 5, wherein the dispersion has a viscosity between 10 cP and 50 McP, as measured by Brookfield method at a temperature between 18° C. and 22° C., and wherein the fiber dispersion comprises more than 90% of fibers with a length, measured at a pH between 1 and 2, is in a range from 1 μm to 2500 μm and with a diameter in a range from 0.1 μm to 150 μm. 
     
     
         2 . The collagen ink for 3D printing according to  claim 1 , wherein at least 90% of a mass of collagen fibers of the dispersion comprises fibers with the length in a range from 50 μm to 2500 μm. 
     
     
         3 . The collagen ink for 3D printing according to claim  claim 1 , wherein 75% of a mass of collagen fibers of the dispersion comprises fibers with the length in a range of 50 μm to 1000 μm. 
     
     
         4 . The collagen ink for 3D printing according to  claim 1 , wherein 50% of a mass of collagen fibers in the dispersion comprises fibers with the length in a range between 100 μm and 500 μm. 
     
     
         5 . The collagen ink for 3D printing according to  claim 1 , wherein 80% of a mass of collagen fibers comprises fibers with the diameter is between 5 μm and 35 μm. 
     
     
         6 . The collagen ink for 3D printing according to  claim 1 , wherein the concentration is between 1% and 5%. 
     
     
         7 . The collagen ink for 3D printing according to  claim 1 , wherein the pH is between pH 1 and 3. 
     
     
         8 . The collagen ink for 3D printing according to  claim 1 , wherein the viscosity is between 2 McP and 15 McP. 
     
     
         9 . A hydrogel comprising the collagen ink according to  claim 1 . 
     
     
         10 . A method of obtaining the collagen ink according to  claim 1  from a collagen-containing tissue, the method comprising the steps of:
 a) washing and chopping a collagen-containing tissue to obtain a chopped tissue; 
 b) chemically macerating the chopped tissue in a controlled manner; 
 c) washing the product obtained from step b) with water; 
 d) adjusting the pH of the product obtained in c), to between 0.5 and 5 to swell the product of step c): 
 e) mechanically mincing the product of step d); 
 f) dispersing the product of step e) in water to a concentration between 0.1% and 10%. 
 
     
     
         11 . The method according to  claim 10 , wherein the collagen-containing tissue is a connective tissue. 
     
     
         12 . The method according to  claim 11 , wherein the connective tissue is a dermis tissue of corium. 
     
     
         13 . The method according to  claim 10 , wherein the connective tissue is of bovine origin, with an age between 1 and 3 years. 
     
     
         14 . The method according to  claim 10 , wherein step c) is carried out in the presence of an alkaline agent. 
     
     
         15 . The method according to  claim 10 , wherein step d) it is acidified between 1 and 3. 
     
     
         16 . The method according to  claim 10 , further comprising a step of homogenizing a precipitate obtained in stage d) prior to stage e). 
     
     
         17 . The method according to  claim 10 , wherein the dispersing is carried out at a concentration between 1% and 5%. 
     
     
         18 . A method of printing 3D structures, the method comprising:
 obtaining the collage ink according to  claim 1 ,   printing a 3D structure with the collage ink.   
     
     
         19 . Structures comprising the collagen ink according to  claim 1 . 
     
     
         20 . A method of printing a structure, the method comprising:
 obtaining the collagen ink according to  claim 1 ;   obtaining cells;   neutralizing the collagen ink to a physiological pH;   mixing the collagen ink and the cells;   printing the structure with the mixed collagen ink and cells.   
     
     
         21 . The method according to  claim 20 , wherein the cells are selected from the group consisting of astrocytes, embryonic cardiomyocytes, fetal cardiomyocytes, neonatal cardiomyocytes, cardiomyocytes, embryonic ventricular myocytes, corneal endothelial cells, corneal epithelial cells, iris pigment epithelial cells, retinal pigment epithelial cells, fetal dopamine neuronal cells, fetal neocortical neuronal cells, enteric neuronal cells, hepatocytes, adipose tissue mesenchymal stem cells, bone marrow mesenchymal stem cells, osteoblasts, chondrocytes, pancreatic cells, and urothelial cells. 
     
     
         22 . The method according to  claim 20 , wherein the physiological pH is between 7 and 8. 
     
     
         23 . The method according to  claim 20 , wherein the mixing is homogeneous. 
     
     
         24 . The method according to  claim 20 , wherein the neutralizing is carried out with salts or buffers selected from the group consisting of phosphate buffer saline (PBS 1× and 10×), Tricine, MOPS, HEPES, Tris, and sodium carbonate.